From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Testing of A.T. speedometers and requesting a standard instrument for calibration.
| Identifier | ExFiles\Box 50\4\ Scan157 | |
| Date | 16th December 1927 | |
| To BY. {R.W. Bailey - Chief Engineer} from EFC. {E. Fowler Clarke - Electrical Engineer} X4308 EFC {E. Fowler Clarke - Electrical Engineer} 7/T16.12.27. 728 A.T. SPEEDOMETERS. Recently we tested one of the A.T. speedometers belonging to one of the grouped instrument board on 14-EX., and we found the reading of this to be rather low. In view of the unlikelihood of these white faced instruments being made standard, it would appear to be more to the point to test one of the latest deliveries of speedometer as at present standard, and I should be pleased if you could arrange for one of these to be handed to us for this purpose. I am given to understand that such a speedometer should read 47 m.p.h. at 600 r.p.m. If you can give me the independent confirmation of the accuracy of this requirement I should be obliged. We can test these instruments at a very accurately measured speed of 600 r.p.m. EFC. {E. Fowler Clarke - Electrical Engineer} | ||